Mia's parents thought she just had the flu. Weeks later, her arms and legs were amputated.

Like so many four year olds, Mia Wilkinson loved visiting the playground and playing with dolls. She was happy-go-lucky and healthy, just beginning to learn how to ride a bike.

Then one fateful night in October 2017, Mia complained to her parents Amy and Peter of a stomach ache.

“About 5pm she threw up,” her mother Amy recalled on Channel 7’s Sunday Night. Amy and Peter put Mia to bed, assuming gastro, but by Saturday morning her parents knew something wasn’t right.

Amy and Peter Wilkinson share Mia’s story on Sunday Night. Post continues below audio.

A trip to the doctor confirmed gastro, but by the afternoon Mia was much worse. They took her straight to the emergency room.

Mia, now 6, was diagnosed with a standard case of flu and was told to go home and get some rest.

“We sort of had this gut feeling [that something more was wrong],” Amy said. “Should we have been louder? But we’re not really pushing people.”

A day later, Amy went to check on her daughter, who had been in bed all day, lethargic, not eating or drinking. That’s when Amy noticed a light purple rash on Mia’s legs.

“If she wore leggings, I wouldn’t have seen it,” Amy said through tears. “I would’ve put her to bed and she shares a room with [eight-year-old sister] Ellie and that would just be horrible.”

They again rushed to hospital and it became very clear Mia needed immediate medical attention. After seeing Mia, a nurse beckoned them straight in, then medical staff were “everywhere”, Peter said.

“She had influenza A, influenza B, RSV, which is another virus, [and] invasive strep A bacterial infection which resulted in sepsis,” explained Amy.

Her lungs were struggling and her organs were shutting down, so doctors needed to intubate her.

Doctors told Amy and Peter to get a cup of tea, to avoid seeing the intubation, but as they returned they heard people yelling out "We're losing her".

Mia had septic shock, which sepsis specialist Dr Luregn Schlapbach told Sunday Night he was not sure she'd survive.

Mia's heart was struggling to pump enough blood to the different organs and her blood pressure was critically low. Medication was used to keep it high enough to support her vital organs, but blood was not getting to her limbs.

Starting with her fingertips, her parents noticed Mia's skin changing colour. First grey, then dark purple, then black.

Doctors advised that amputation would be best and Amy vividly remembered the moment they had to tell Mia what was coming.

"We're not going to not tell her. You can't send a child in and not tell them they're going to have their arms amputated... [We had to tell her] they can't save your hands and feet. They can't make them better. She was upset: 'I don't want them to take my hands.'

"She's like, 'How will I play with Ellie?"

Just a few weeks after her hospital admission, Mia's arms were amputated below the elbow. Following this, Mia was allowed to go home for a few days before returning to hospital for the amputation of her legs below the knee.

"We took her home [so] we could have Christmas at home, which was good but hard," said Amy. "Christmas shouldn't be like that."

"Then she went back in for her leg amputation surgery on the 3rd of January."

A year and a half on, Peter and Amy told the show they were so proud of how Mia has adapted to her new normal. She's resilient, determined and most importantly: Happy.

She's learned to draw and write with no hands and walk on prosthetic legs. Mia also loves swimming.

Amy and Peter have set up Movement for Mia to both raise awareness about sepsis and to raise funds for Mia's ongoing medical expenses and prosthetics. She outgrows her prosthetic limbs about every six months.

They want every parent to learn from Mia's story.

"If your child is the sickest that you've ever seen them, tell that doctor that you speak to," Peter said. "Make them understand how serious you think it is. And get vaccinated. You don't want this. Get the flu shot."

This flu season is the second-deadliest on record, with more than 120,000 cases of lab confirmed influenza reported up to the end of June and 231 deaths.